The present invention relates to electronic scales. More specifically, this invention relates to a handheld electronic scale having a unique hinge operation and removable weighing tray.
There are a number of patents for scales including U.S. Pat. Nos. 4,034,818; 4,041,289; 4,195,348; 4,495,581; 4,800,973; 6,177,929; 6,295,198; and 6,381,484, incorporated herein by reference.
Typically, with an electronic scale, an object is positioned on a weighing platform, so that the weight of the object causes the weighing platform to move downward. The downward force causes the weighing platform to exert a force or pressure on a transducer. The transducer converts the downward force into an analog signal in terms of a voltage or a current having a magnitude which varies according to the weight of the object.
Compact portable scales have a number of disadvantages. One disadvantage of compact portable scales is the small weighing platform; making it difficult to weigh objects and loose items. Another disadvantage for compact portable scales having a hinged lid is that the hinge and/or lid interferes with the weighing process, especially when oversized objects are to be weighed.
The hand-held scale of the present invention comprises a portable electronic weighing device having: (a) a housing comprising a base and a lid, the base connected to the lid with a hinge, wherein the hinge operates to pivot the lid relative to the base between a closed position covering a weighing platform and an open position exposing the weighing platform, wherein the lid is rearwardly positioned relative to the weighing platform, and wherein the hinge includes damping means to effectuate controlled pivotal motion between the open and closed positions; (b) a removable tray having an underside fitted to sit on the weighing platform, wherein the underside of the removable weighing tray comprises a flanged edge sized to extend around the edge of the weighing platform, and an upper surface providing a larger surface area than the weighing platform, wherein the upper surface of the weighing tray is cupped for holding the object to be weighed; (c) weighing circuitry in the base in communication with the platform for weighing objects to provide weight data thereof; and (d) a display located on a front surface of the base for digital display of weight data of the object. The housing includes a pair of flanges extending from opposite side edges of the housing in parallel spaced relationship and hinge forming trunnions being formed on inwardly facing surfaces of the flanges. The hinge comprises a tubular portion formed along one edge of the lid extending between the trunnions, the tubular portion including cylindrical bores extending along the longitudinal axis thereof and the damping means arranged in one of the bores. The weighing circuitry comprises a transducer coupled to the platform responsive to the weight of the object to provide an analog signal indicative of the weight, and comprising analog to digital conversion circuitry for providing the weight data. The damping means comprises a helical coil spring. In an embodiment, the portable electronic weighing device further includes a spring-biased latch mounted in the housing for engaging the lid to maintain the lid in a closed position over the weighing platform, the latch being manually operable to release the lid.
All patents, patent applications and publications referred to or cited herein, or from which a claim for benefit of priority has been made, are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of this specification, including: U.S. Pat. No. 4,041,289 to Brosh et al., U.S. Pat. No. 6,085,384 to Bivens, and U.S. Pat. No.